Questions tagged [summing]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
6 votes
5 answers
1k views

Mixing audio signals: pros and cons of using resistors instead of an op-amp

I'm working on a project that requires me to mix two audio signals from two sources (both on the same PCB). Source one is an audio output coming from the the VS1053B MP3 Audio CODEC IC, and source two ...
Jay's user avatar
  • 1,195
0 votes
1 answer
66 views

Adding four numbers of 1 bit each and then cascading them

When I add four bits (NOT FOUR BIT ADDER, only four bits), the result can go to a maximum of 100 (4 in decimal, if all are ones). Now, here 0 (LSB) is the sum and 10 is carry. If I want to transfer ...
Shehryar Kashif's user avatar
4 votes
2 answers
276 views

Summing Op-Amps vs Difference Op-Amps

How do you tell the difference between a summing amplifier (non-inverting) op-amp and a difference amplifier just by looking at its configuration? Please note that in both of these cases, both the (+) ...
HDY's user avatar
  • 49
1 vote
4 answers
188 views

Why does the current not divert in the inverting summing amplifier circuit?

Why is the current drawn from different sources in this circuit not diverted to other resistors? Why does current only flow through the Rf resistor?
Doğukan Karakaya's user avatar
2 votes
4 answers
477 views

Summing Amplifier Supply Voltage

Consider the case that I have a standard inverting summing amplifier with two inputs: 0.5V DC and 1V DC. Therefore, the output of the amplifier should be -1.5V related to GND. However, If I connect ...
Aurora7979's user avatar
5 votes
5 answers
1k views

Single-supply non-inverting op-amp for summing DC voltages at unity gain

Is it possible to use this single supply, non-inverting, summing op-amp configuration to sum multiple arbitrary DC voltages at unity gain? I've used the inverting summing op-amp config on bipolar ...
formerlolz's user avatar
1 vote
2 answers
48 views

PGA207 Feedback Issue Modification

I have mistakenly used an instrumentation op-amp (PGA207) in the place of a normal op-amp in my design, so now I have to make adjustments to my circuit. A snippet of the datasheet from the op-amp I ...
Adriaan Sadie's user avatar
4 votes
3 answers
679 views

DC voltage summing type circuit

I hope someone can help me. I'm not an electrical engineer by occupation. I have a need for a circuit that can do the following: Provide a steady 8 V DC output at rest. Add to that output, the voltage ...
Darren's user avatar
  • 41
1 vote
1 answer
79 views

How to LPF only one of the inputs to a voltage adder?

I'm taking voltages from two inputs, and I'd like to add them together using an op amp (this is actually a summing integrator). I would like to filter out the noise in V_DAC (which will not change ...
Jonathan Wheeler's user avatar
0 votes
1 answer
105 views

Buffer with parallel capacitors

Hello I am trying to build the following 3 band equalizer for a project. As I am analyzing the circuit I've come to a problem. I do understand what the "second stage" does: It's a summing ...
Jose Rios's user avatar
2 votes
3 answers
1k views

Design methodology for non-inverting summing op-amp

I'm trying to design an op-amp circuit to sum up four voltages by using a non-inverting summing configuration. You can see it in the circuit below, though for illustration's sake, the resistor values ...
BestQualityVacuum's user avatar
0 votes
2 answers
327 views

Where to add equalization in active audio mixer?

I want a 2-input summing amplifier where I can adjust the amount of signal from each source with a single potentiometer. I intend to hook up two microphones (Shure SM57 and Audio Technica ATR 1500, ...
Walden Marshall's user avatar
2 votes
1 answer
335 views

Is there a simple fix for summing 2 AC signals?

I have seen many mixer schematics. They are pretty much always the same - a stack of resistors. Even some DJ mixers using the SSM2164 simply joined outputs followed by an opamp. The same thing always ...
NaturalDemon's user avatar
2 votes
1 answer
198 views

Multiple LM35 temperature sensors with summing amplifier?

I have two big heatsinks with four power MOSFETs on each of them, I want to control the temperature of each heatsinks so that doesn't exceed 80℃ using two LM35 temperature sensors: simulate this ...
ElectronSurf's user avatar
  • 2,356
0 votes
3 answers
207 views

Floating/open input on summing amp

I was tasked with taking a signal that could be of ±2.5 and converting it to 0-5v so it could be read by an ADC. I managed that with a non-inverting summing amp like so: It worked pretty well but I ...
Kristhian Otero's user avatar
1 vote
1 answer
438 views

Stereo channel strip based on NE5532

I want to build a stereo channel strip, using the NE5532 IC. It should feature 2 mono inputs with volume control, mute switch and pan control going to a stereo output with unity gain. In the schematic ...
nefaricon's user avatar
1 vote
1 answer
661 views

FFT analysis of summed signal in LTSpice

I know that simulating FFT analysis of current/voltage across a single element via LTSpice is quite straightforward. I have simulated the summation of three distinct currents in the time domain. I'd ...
Ady's user avatar
  • 83
0 votes
2 answers
325 views

How do I create a 1-bit full adder that outputs a 2-bit sum?

I am trying to build a 1-bit full adder that outputs a 2-bit sum. I know that the standard 1-bit FA outputs a 1-bit sum and a carry bit, but I was wondering how can I modify the FA such that the carry ...
Adam Lee's user avatar
  • 113
1 vote
1 answer
293 views

Summing stereo and mono channels passively

I am trying to build a headset for use on my motorcycle which will allow me to listen to my music from my phone (stereo signal) and the incoming sound from my UHF radio (mono i'm pretty sure). what is ...
JoshB's user avatar
  • 11
1 vote
1 answer
352 views

3-to-2 line encoder (or generally 2^(n-1)-to-n) -- not priority, but telling how many inputs are on?

This is not homework (not taking any classes) although it could be homework. I am wondering what is the easiest implementation using a single TTL chip or gates (fewest chip count) to encode the number ...
Gunther Schadow's user avatar
0 votes
3 answers
1k views

Summing integrator cut-off frequency

I would like to know how to calculate the cut-off frequency of this summing integrator circuit. I can't find anywhere on the internet how to calculate the cut-off frequency in this configuration. ...
Sundark12's user avatar
1 vote
4 answers
14k views

How do you combine 2 AC power sources?

To combine 2 DC power sources, you can diode OR them both together. You can't just directly connect them together because their voltage outputs may differ ever-so-slightly, leading to imbalanced ...
Gabriel Staples's user avatar
1 vote
3 answers
907 views

Is there a limit to the number of inputs that can be summed with an op-amp summing circuit?

I'm interested in the limits you encounter if you try to add many inputs into an op amp summing circuit. I've read that the inverting configuration is more natural for adding many inputs since the ...
Bob789's user avatar
  • 13
2 votes
0 answers
68 views

Summing Audio Channels

I’m trying to sum my car stereo output. Factory output has bass on one output and mid and tweeter on another output giving me 2 channels for left and 2 channels for right. Ideally I’d like to sum ...
Phils Channel Various Stuff's user avatar
0 votes
1 answer
190 views

Why is my mixer circuit lowering the signal?

I have made a really simple mixer, to be used with both audio and control signals in a modular system: This should if I understand it correctly give "about" 1:1 (1:0.99 in simulation) ratio beetween ...
Sourcery's user avatar
  • 153
0 votes
1 answer
206 views

Voltage level shifter using op amp

I am making a circuit to acquire EOG signals and read it via the analog pin of Arduino. The Arduino reads only positive signals, which is why I am unable to see the negative spikes in voltages caused ...
Pranav Shah's user avatar
0 votes
2 answers
322 views

Noise on stereo summing circuit from LED's

I've been a tinkerer and hobbyist for 20 years now, but mostly in software. I've done my fair share of simple soldering (replaced controller ports on an original Xbox with actual USB ports, for ...
pdm's user avatar
  • 101
3 votes
5 answers
3k views

Non-inverting op-amp audio mixer

I am trying to make sense of the difference between non-inverting and inverting op-amp based audio "mixers". The circuits are basically summing op-amp amplifiers. Here is the part which I do ...
Jüri Bogatkin's user avatar
0 votes
0 answers
39 views

Help in analysing circuit to show which resistor controls the differential gain

I understand the circuit to be a summing circuit but I am struggling to analyse past this point: Vout = R5 (((-R2/R1 * V2)/R4) * (V1 / R3)). can anyone analyse this further to prove that R5 is the ...
mwilliams25's user avatar
0 votes
2 answers
62 views

Help with my design: How can I add these voltages?

I have to design a circuit that simulates a voltage spike on a dc supply rail. The circuit has a button that, when pressed, generates a short pulse of controllable height (controlled by pot). The ...
Mode77's user avatar
  • 101
6 votes
4 answers
4k views

How do solar inverter systems easily add AC power sources together? [closed]

I understand DC power more than AC power. I know that given multiple DC power generators, easiest way to sum them is by connecting them in series. In paralel you'd need every generator circuit to ...
Evan's user avatar
  • 199
4 votes
3 answers
1k views

Don't individual signal sources affect each other when using a summing amplifier?

I am studying the book Electric Circuits by Nilsson & Riedel. There I learned about "summing amplifiers" and how to derive equations by applying KCL at inverting input of the op amp. I see that ...
alpersunter's user avatar
0 votes
1 answer
217 views

summing amp - floating inputs

I'm designing an audio mixer and currently i'm working on a cue section. The whole point is that i have 2 or more channels and want to mix them in summing mixer. You can turn off the channels you don'...
cubix's user avatar
  • 233
0 votes
1 answer
307 views

Practical considerations for a summing amplifier

The summing (usually inverting) amplifier is a classic op amp configuration. However, I'm struggling to find any products on the market which actually do this, leading me to conclude that I have to ...
CharlieB's user avatar
  • 229
0 votes
1 answer
631 views

Adding multiple differential signal

As I asked in "Adding multiple analog signal" before, I got that: for adding some signal together, we can only use op-amp, instead of lovely integrated circuit (ough). But the question arise because ...
mohammadsdtmnd's user avatar
2 votes
3 answers
589 views

Mathematically derived waveform vs. captured waveform from an analog synthesizer

I was thinking about how the individual parameters on an analog synthesizer could be controlled digitally. What I mean is, instead of using mechanical potentiometers to adjust some quality of the ...
i0oklng 1lke c0nfus10n's user avatar
0 votes
2 answers
589 views

Adding large numbers in context of analog computing?

I have been reading about analog computing yet have not been able to find material about a certain issue; in reference to arithmetic, it is said that op-amps are used to perform these tasks, for ...
NBoss's user avatar
  • 230
0 votes
3 answers
836 views

Connecting signal to multiple summing amplifiers

For a normal op-amp inverting summing amplifier, each signal is tied to the negative input of the op-amp. Imagine the scenario where I have three signals. In adder 1, I want to sum A and B. In adder 2,...
Ashton Snelgrove's user avatar
1 vote
1 answer
213 views

Instrumentational Amplifier with Summing Amplifier

As you all know, most Inst. Amp. examples on the Internet have a 'Differential Amplifier' part as shown below. But, what would happen if a summing amplifier was used instead ? What kind of ...
PIC16F84A's user avatar
  • 172
0 votes
0 answers
80 views

Summing Configuration Question

I'm building the following circuit in a PCB . The purpose is simple, the first stage is a TIA amplifier that converts current into voltage and its working fine. The second stage, where the problem is ...
Impe_dancer's user avatar
0 votes
1 answer
251 views

LTSpice simulation errors?

I ran this simulation in ltspice and my output voltage was -2.97V. According to my calculations I should have roughly -10V when all sources are at 5V. $$V_{out} = -V_{in}R_5 \left ( \frac{1}{R_1} + \...
user avatar
13 votes
3 answers
5k views

Accidentally downmixed stereo to mono, why does this work?

I have a cheap Chinese Bluetooth audio amplifier like this: It has four screw terminals for the speaker connections, namely L+, L-, R+ and R-. I accidentally connected a single speaker to L+ and R-, ...
Bas's user avatar
  • 463
2 votes
1 answer
851 views

What's the best way to mute summed stereo channels?

I am building an audio mixer, and most of the instruments produce mono signals (internally split to L/R), but want to make sure it is flexible enough to use true stereo devices, and sum to mono in my ...
Jay's user avatar
  • 359
1 vote
3 answers
590 views

How can I add high and low voltage signals to a high voltage DC offset?

It's only a theorethical question, since I'm not really going to build this circuit... I'm just curious, that's all. Anyway, thats my question! I have these signals: 3 kHz, 1V (peak) 20 Hz, ...
keeper1h's user avatar
0 votes
3 answers
480 views

Eliminating attenuation in summing box

Full disclosure: when it comes to electronics, I'm the type that knows enough to be dangerous. And that's kinda why I'm here - I took an electronics course in high school in 2005, but it's been a ...
p0lar_bear's user avatar
1 vote
1 answer
57 views

Does a Series Voltage Reference referencing more than one electrical block has to be buffered?

I'm planing to use a Series Voltage Reference,REF3330, as a voltage reference to three distinct parts of my circuit and i need an opinion regarding the way how to do it. First of all, the reference ...
Impe_dancer's user avatar
0 votes
2 answers
1k views

Can I use a Class D amplifier as a summing amplifier?

Context: I'm creating a mono, battery powered speaker. I'd like to sum the left and right channels of a stereo input signal into a mono output signal, which I feed into a Class-D Mono Audio Amplifier ...
LukeGT's user avatar
  • 103
0 votes
1 answer
553 views

Summing amplifier with one op amp

I want to design amplifier that do the following summation $$V_o = 2V_1 +3V_2 +5V_3 $$ the difficult arose when design with one op-amp and all voltages are referenced to the ground . I tried with ...
Mohamd ahmed's user avatar
0 votes
1 answer
189 views

When to treat transformers as non-ideal?

For an experiment I need to sum a DC and AC Potential. My solution to this was to construct the following circuit: simulate this circuit – Schematic created using CircuitLab Testing this ...
Edgar P's user avatar
  • 51
10 votes
3 answers
24k views

Inverting summing amplifier vs Non-inverting summing amplfier

As known there are inverting and non-inverting summing circuits, such as below: What's their cons and pros?
diverger's user avatar
  • 5,858